I'm planning on creating a mirrored server to be stored at an offsite facility. I'm going to get software that would replicate any changes made on the "master" server to the "backup" server. I've actually got 2 servers that I will be replicating to duplicate backup servers. My question is this: Do I need to buy more licenses for the backup servers? Since the backup servers will only be used in the event that my production servers are offline, it seems that I would be within Microsoft requirements for licenses. So if I've got 100 CAL's, can I just replicate them to the backup servers, or will I have to buy another 100 licenses specifically for the backup servers?